Frame bend radius

[Eitek1]

Does anyone know what the bend radius is on the simplex frames? I have a buddy that bought a frame and wants to do something with it. The problem is the bend below the motor is halfway rusted through. I was planning on sectioning that piece out and welding in an new piece. It sure would help if I knew what radius shoe was needed to make that bend.

Any ideas?

[kartjockey]

Went out to my bare 1952 frame and came up with this.  3 1/2" radius.  I don't why it came as a surprise to me but the radius around the tank and at the motor mount are a match.  It makes  sense for them to be the same so they didn't have to change out the shoe. Some where I thought I had a photograph of the plant manufacturing the frames.  Not sure. (template is for around the tank)

[Eitek1]

Thanks Tom... I figured it was a 3.5" but didn't know for sure.

I'm getting ready to work on mine over the winter. Life gets in the way of my hobbies.